Syringe apparatus with threaded plunger for delivering tooth composites and other solid yet pliable materials

ABSTRACT

A syringe apparatus is disclosed for delivering solid, yet pliable materials, such as dental composites. The syringe apparatus of the present invention comprises an unthreaded barrel means for containing the material. The unthreaded barrel means has an inlet end, an outlet end, and an enlarged finger grip at the inlet end. The syringe apparatus also comprises means for slidably engaging the finger grip of the barrel means, the engaging means having a threaded throughbore. The syringe apparatus further comprises a plunger means for movement through the barrel means. The plunger means has a threaded portion that is complementary to the threaded throughbore of the engaging means, such that the plunger means may be advanced into the barrel means at the inlet end by applying an external rotational force to the plunger means relative to the barrel means, thereby effecting delivery of the material at the outlet end of the barrel means. Finally, the threaded throughbore of the engaging means and the threaded portion of the plunger means are configured such that the plunger means will automatically withdraw slightly from the barrel means when the external rotational force is removed from the plunger means, reducing the amount of pressure exerted by the plunger means on the material within the barrel means.

This application is a continuation of U.S. application Ser. No.08/411,090, filed Mar. 27, 1995, now abandoned for Syringe ApparatusWith Threaded Plunger For Delivering Tooth Composites And Other SolidYet Pliable Materials.

BACKGROUND

1. Field of the Invention

This invention relates to syringe systems that are used for storing anddispensing materials therefrom, and more particularly to a hand-operateddental syringe that is capable of efficiently storing a solid, yetpliable material, such as a dental composite material or a lightactivating composite which cures with exposure to an activating light,and extruding precise amounts of the composition from the dentalsyringe.

2. Prior State of the Art

Various types of syringes have heretofore been used in dentalapplications, including for storing and dispensing highly viscous orsolid, yet pliable dental composites. For example, standard push-typesyringes comprising a barrel and a plunger may be used for suchpurposes. However, especially with solid, yet pliable dentalcompositions, it is often difficult to generate the pressure needed toexpress the material through the outlet opening by exerting pressure onthe syringe plunger in a longitudinal direction. Another serious problemis that once sufficient pressure is applied to the plunger, it isdifficult to precisely control the amount of material expelled throughthe outlet opening of the barrel, thereby resulting in waste of theexcess material.

To overcome some of these problems, syringes having a threaded barreland a threaded plunger have been used to extrude dental compositions. Anexample of such a syringe is illustrated in FIG. 1. The syringe 110comprises a barrel 112 and a plunger 114. Barrel 112 has a central bore116, an inlet end 118, an outlet end 120, and a threaded insert 122located at the inlet end 118. The plunger 114 has a proximal end 124, adistal end 126, a threaded stem 128, and a T-shaped head 130. Thethreads of threaded stem 128 are complementary of, and configured tomate with, the threaded insert 122 of the barrel 112. By inserting thedistal end 126 of plunger 114 into threaded insert 122 of barrel 112 androtating plunger 114 relative to barrel 112 in a clockwise direction,the distal end 126 of plunger 114 is progressively advanced into thecentral bore 116 of barrel 112. Threaded insert 122 and threaded stem128 cooperate to translate external rotational forces applied toT-shaped head 130 into longitudinal forces applied through the distalend 126 of plunger 114 to the material contained within the central bore116 of barrel 112. It will be appreciated by those skilled in the artthat the use of the threaded barrel and threaded plunger combinationmakes it easier for the user to generate the forces needed within barrel112 to extrude the material out of the outlet end of barrel 112.

However, the threaded syringes found in the prior art have somesignificant disadvantages. First, such syringes require speciallydesigned and fabricated syringe barrels, which are more difficult andmore expensive to manufacture than standard, unthreaded push-typesyringe barrels. In addition, such threaded syringe barrels can only beused with threaded plungers and are not, without modification,compatible or interchangeable with standard push-type plungers.

An even more serious disadvantage of the threaded syringes found in theprior art is that they do not provide any means for relieving thepressure built up within the barrel when the external forces are removedfrom the syringe plunger. As shown in FIG. 1, the prior art syringestypically include relatively fine threads, which result in a relativelyhigh coefficient of friction between the threaded insert 122 of barrel112 and the threaded stem 128 of plunger 114. Those skilled in the artwill appreciate that significant pressures can be generated withinbarrel 112 as plunger 114 is advanced into barrel 112 by rotatingplunger 114 relative to barrel 112, particularly when solid, yet pliabledental compositions are situated within barrel 112. Once the externalrotational forces are removed from plunger 114, the fine pitch of thethreads coupled with the friction between threaded insert 122 andthreaded stem 128 prevent the pressure built up within barrel 112 fromforcing plunger 114 to back out from within barrel 112. Instead, thepressure built up within barrel 112 continues to force the dentalcomposition to flow through the outlet end 120 of barrel 112, even afterthe external forces have been removed from plunger 114, therebyresulting in waste of the excess material.

Yet another disadvantage associated with the threaded syringes found inthe prior art is that the fine threads used in such devices collectdebris and other contaminants which, in turn, make it more difficult tosterilize and maintain the sterile condition of the device.

BRIEF SUMMARY AND PRINCIPAL OBJECTS OF THE INVENTION

The present invention seeks to resolve the above and other problemswhich have been experienced in the art. More particularly, the apparatusof this invention constitutes an advancement in syringe art by providinga novel syringe system which achieves each of the objects listed below.

It is an object of the present invention to provide a syringe apparatusthat enables the efficient storage and dispensing of solid, yet pliablematerials, such as dental composites.

It is another object of the present invention to provide a syringeapparatus that is capable of metering precise amounts of the compositematerial dispensed therefrom.

It is another important object of the present invention to minimize thewaste of the composite material.

It is yet another important object of the present invention to provide asyringe apparatus that automatically relieves the pressure built upwithin the syringe barrel when the external force is removed from thesyringe plunger.

It is an important object of the present invention to provide a syringeapparatus comprising a syringe barrel that can be utilized with either astandard push-type plunger or a threaded, rotation-type plunger.

Yet another object of the present invention is to provide a threadedsyringe apparatus that utilizes a standard push-type syringe barrel.

Still yet another object of the present invention is to provide a meansfor retrofitting a standard push-type syringe barrel for use with athreaded syringe plunger.

Additional objects and advantages of the invention will be set forth inthe description which follows and, in part, will be apparent from thedescription or may be learned by the practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims.

To achieve the foregoing objects, and in accordance with the inventionas embodied and broadly described herein, the present inventioncomprises a syringe apparatus of multi-dose capability which enables theremoval of material therefrom in a predictable manner. The syringeapparatus of the present invention comprises an unthreaded barrel meansfor containing the material. The unthreaded barrel means has an inletend, an outlet end, and an enlarged finger grip at the inlet end. Thesyringe apparatus also comprises means for slidably engaging the fingergrip of the barrel means, the engaging means having a threadedthroughbore. The syringe apparatus further comprises a plunger means formovement through the barrel means. The plunger means has a threadedportion that is complementary to the threaded throughbore of theengaging means, such that the plunger means may be advanced into thebarrel means at the inlet end by applying an external rotational forceto the plunger means relative to the barrel means, thereby effectingdelivery of the material at the outlet end of the barrel means. Finally,the threaded throughbore of the engaging means and the threaded portionof the plunger means are configured such that the plunger means willautomatically withdraw slightly from the barrel means when the externalrotational force is removed from the plunger means, reducing the amountof pressure exerted by the plunger means on the material within thebarrel means. Additionally, the syringe apparatus is comprised ofmaterials which block transmissive activating light so as to avoidunwanted exposure of the unextruded light-activating material within thesyringe apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more fully understand the manner in which the above-recitedand other advantages and objects of the invention are obtained, a moreparticular description of the invention briefly described above will berendered by reference to specific embodiments thereof which areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are therefore notto be considered limiting of its scope, the invention and the presentlyunderstood best mode for making and using the same will be describedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 is a cross sectional view of an assembled prior art device, takenalong the center longitudinal axis.

FIG. 2 is perspective view of one presently preferred embodiment of thepresent invention.

FIG. 3 is an exploded isometric view of one presently preferredembodiment of the present invention.

FIG. 4 is a detailed, cross sectional view of one presently preferredembodiment of the syringe barrel of the present invention taken alongthe center longitudinal axis.

FIG. 5 is a detailed, exploded cross sectional view of one presentlypreferred embodiment of the syringe plunger and the plunger plug of thepresent invention.

FIG. 6 is a detailed, cross sectional view of the top portion of onepresently preferred embodiment of the of the syringe barrel with theattachment means in place, mated with the finger grip of the syringebarrel.

FIG. 7 is a detailed perspective view of a portion of one presentlypreferred embodiment of the outlet end of the syringe barrel.

FIG. 8 is a detailed perspective view, with partial cut-away, of onepresently preferred embodiment of the outlet end of the syringe barrel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is broadly described as a syringe apparatus fordelivering materials that are highly viscous or essentially solid, yetpliable. Referring generally to FIGS. 2 and 3, the syringe apparatus,generally designated 10, comprises a barrel means 12, a means forslidably engaging the barrel means 14, and a plunger means 16.

Barrel means 12 has a central bore 18, a proximal or inlet end 20, and adistal or outlet end 22. The barrel 12 also has an outer surface 24,which has a smaller outer diameter at distal end 22. Barrel 12 also hasa shoulder 26 between distal end 22 and outer surface 24. Barrel 12terminates at its proximal or inlet end 20 in an integrally formed,enlarged finger grip 28, which is configured to accommodate the fingersof the user when the barrel is used with a standard, nonthreadedpush-type plunger (not shown). Finger grip 28 is generally planar and isoriented perpendicular to the longitudinal axis of barrel 12. As bestillustrated in FIG. 3, finger grip 28 has rounded sides 30 and 32located on two opposing sides, and two flat, parallel sides 34 and 36located on the other two opposing sides. As further illustrated in FIG.3, the distance across finger grip 28 from flat side 34 to flat side 36is less than the diameter measured across the rounded sides 30 and 32 offinger grip 28. Further, finger grip 28 provides a generally smooth,planar top surface 38 and a generally smooth, planar bottom surface 40.

As discussed in more detail below, engaging means 14 has slots orchannels 42 and 44 configured to receive finger grip 28 of the barrel 12in mating, press fit relationship. Engaging means 14 has a generallyplanar portion 46, the shape of which corresponds very closely to theshape of finger grip 28 described above. Planar portion 46 has roundedsides 48 and 50 located on two opposing sides, and two flat, parallelsides 52 and 54 located on the other two opposing sides. Planar portion46 provides a generally smooth, planar top surface 56 and a generallysmooth, planar bottom surface 58. Integrally formed at the outer edgesof flat sides 52 and 54 are two side wall portions 60 and 62, which areoriented perpendicular to planar portion 46. Integrally formed at thedistal ends of side wall portions 60 and 62 are flanges 64 and 66, whichare oriented perpendicular to, and extend inwardly from, side wallportions 60 and 62. Bottom surface 58, side wall portions 60 and 62, andflanges 64 and 66 cooperate to form slots or channels 42 and 44 forreceiving the flat sides 34 and 36 of finger grip 42 in sliding, pressfit engagement. As further shown in FIG. 3, flanges 64 and 66 areslightly chamfered so as to guide finger grip 42 into engagement withengaging means 14. In addition, the lateral separation between thedistal ends of flanges 64 and 66 is slightly less than the outsidediameter of barrel 12 adjacent to finger grip 42, so as to providesecure engagement between finger grip 42 and engaging means 14 whenfinger grip 42 is fully inserted into engaging means 14. Engaging means14 also has a cylindrical portion 68 situated at the center of topsurface 56. Cylindrical portion 68 is formed as an integral part ofengaging means 14. A throughbore 70, with internal threads, passesthrough the center of cylindrical portion 68 and planar portion 46 ofengaging means 14. Cylindrical portion 68 and threaded throughbore 70are situated on engaging means 14 such that they are in longitudinalalignment with the central bore 18 of barrel 12 when engaging means 14is fully engaged over finger grip 42.

Plunger 16 has a proximal end 72, a distal end 74, a threaded stem 76,an unthreaded distal tip 78, and an integrally formed, hexagonallyshaped head 80. The external threads of threaded stem 76 arecomplementary of, and configured to mate with, the internal threads ofthe throughbore 70 of the engaging means 14. The outside diameter of thethreads of threaded stem 76 is approximately the same, yet is slightlysmaller than, the internal diameter of central bore 18 of barrel 12,such that threaded stem 76 will slide with close tolerance withincentral bore 18.

To prevent the dental composite material from flowing back up betweenthe threads of threaded stem 76 as it is advanced into barrel 12, acylindrically shaped plug 82 is provided, which receives the unthreadeddistal tip 78 of plunger 16 in mating relationship. The outside diameterof plug 82 is approximately the same, yet slightly smaller than, theinternal diameter of central bore 18 of barrel 12, such that plug 82will slide with close tolerance within central bore 18. Plug 82 also hasan annular recess for receiving an o-ring of suitable size (not shown)so as to provide a more effective seal against the inner surface ofcentral bore 18. The distal end of plug 82 has a concave surface, whichserves to focus the forces applied through the plunger into the centerof the material and, at the same time, scrape off any material that mayadhere to the inner surface of barrel 12. As will be appreciated, theoutside diameter of plug 82 is larger than the inside diameter of theinternal threads of throughbore 70 of engaging means 14. Accordingly,plug 82 must be inserted into central bore 18 of barrel 12 prior tosliding engaging means 14 onto finger grip 28. With the dentalcomposition material situated in barrel 12 and plug 82 inserted into thecentral bore 18 of barrel 12, engaging means 14 is then slid into placeover finger grip 28 of barrel 12 in the manner described above.

By inserting the distal end 74 of plunger 16 into threaded throughbore70 of engaging means 14 and rotating plunger 16 relative to barrel 12 ina clockwise direction, the distal end 74 of plunger 16 is progressivelyadvanced into the central bore 18 of barrel 12. Threaded throughbore 70and threaded stem 76 cooperate to translate external rotational forcesapplied to head 80 into longitudinal forces applied through the distalend 74 of plunger 16 to plug 82 and, in turn, through plug 82 to thedental composite material contained in barrel 12. It will be appreciatedby those skilled in the art that the use of the threaded plunger makesit easier for the user to generate the forces needed within barrel 12 toextrude the material out of the outlet end 22 of barrel 12. In thatregard, the enlarged head 80 is hexagonally shaped to facilitate ease ofgripping and manipulation by the user. The hexagonal shape of head 80also allows the user efficiently to rotate plunger 16 with a minimalamount of hand and wrist rotation.

Another important feature of the present invention is that it provides ameans for automatically relieving the pressure built up within thebarrel when the external forces are removed from the syringe plunger.Those skilled in the art will appreciate that significant pressures canbe generated within barrel 12 as plunger 16 is advanced into barrel 12by rotating plunger 16 relative to barrel 12, particularly when solid,yet pliable dental compositions are situated within barrel 12. In priorart devices, the friction between threaded barrel and the threadedplunger prevents the pressure built up within syringe barrel fromforcing syringe plunger 16 to back out from within the syringe barrel,even when the external forces applied to the plunger have been removed.Under those conditions, the pressure built up within the syringe barrelcontinues to force the dental composition to flow out the end of thesyringe barrel, resulting in an excessive amount of the material beingexpressed out the end of the barrel and wasted.

In the present invention, however, the internal threads of throughbore70 and the external threads of threaded stem 76 have been speciallyselected and designed to allow plunger 16 automatically to back offsightly, or "snap back," when the external rotational force applied bythe user is removed from plunger 16. As best illustrated in FIGS. 5 and6, the threads of throughbore 70 and threaded stem 76 are fairly coarse,and the teeth of the threads are generally square-shaped. Those skilledin the art will appreciate that these features combine to presentthreads with a relatively low coefficient of friction. Accordingly, oncethe external pressure is removed from plunger 16, the coarse pitch ofthe threads coupled with the relatively low coefficient of frictionallows the pressure built up within barrel 12 to urge or force plunger16 to withdraw slightly from barrel 12, thereby relieving the pressureand stopping the flow of material out of the outlet end 22 of barrel 12.In one presently preferred embodiment, the pitch of the threads ofthroughbore 70 and threaded stem 76 is approximately ten threads perinch. Those skilled in the art will appreciate that the "snap back"effect will be even greater with threads that are more coarse, but thatmust be balanced against the mechanical efficiency of the threads intranslating the rotational force applied to the head 80 of plunger 16into longitudinally oriented forces.

In addition, the number of rotations (or fraction thereof) of plunger 16relative to barrel 12 provides a means for metering the amount ofmaterial expressed from the outlet end 22 of syringe 10. In thepresently preferred embodiment incorporating the ten pitch threads, eachcomplete revolution (e.g., 360 degrees) of head 80 causes plunger 16 toadvance longitudinally a sufficient distance to force just enough dentalcomposite material out the outlet end 22 of barrel 12 to completely fillthe QUADRASPENSE® dispensing tip, which will be discussed in detailbelow. Head 80 is also provided with a raised longitudinal rib along atleast one side thereof, which serves as a reference point to enable theuser to monitor or gauge the number of rotations (or fraction thereof)of plunger 16 relative to barrel 12 and, thus, the amount of materialdispensed out the outlet end 22 of barrel 12.

The present invention may be used with essentially any type oftermination at the outlet end 22 of barrel 12. For example, barrel 12could terminate at its outlet end in a delivery tip of the typedisclosed in U.S. Pat. No. 5,269,684. Alternatively, barrel 12 couldterminate at its outlet end in a simple opening, luer fitting or othertype of fitting commonly used at the distal end of dental or medicalsyringes through which the dental composite material is extruded. Thepresent invention is not limited to any specific type of termination.

In one presently preferred embodiment of the invention, the syringeapparatus 10 terminates at its outlet end in a QUADRASPENSE® deliverytip of the type disclosed in U.S. Pat. No. 5,387,103. As illustrated inFIGS. 3, 7 and 8, barrel 16 further comprises a divider means 84 forsectionalizing and individually compartmentalizing the sectionalizedportions 8a, 8b, 8c and 8d of the material 8. As shown best in FIG. 7,the material 8 becomes sectionalized and individually compartmentalizedas the plunger 16 pushes the material 8 to the outlet end 22 of thebarrel 12. In a presently preferred embodiment, the net result of theaction between the barrel 12 and its associated divider means with theplunger 16 is that the material 8 will be presented beyond the outletend 22 of the barrel 12 in a plurality of individualized sections 8a,8b, 8c and 8d. Each of the individualized sections 8a, 8b, 8c and 8d ofthe material 8 is contained in a separate compartment. Each separatecompartment has a support surface 86 which extends beyond the outlet end22 of the barrel 12. Each section of material 8a, 8b, 8c and 8d lieswithin a compartment formed by the inside surface 88 of the barrel 12,and at least one support surface 86 of a cutting plate 90. Cuttingplates 90 are shown as radially disposed vanes. Each separatecompartment accommodates the removal of a selected portion 8a, 8b, 8cand/or 8d of the sectionalized and compartmentalized part of thematerial 8 in the manner discussed in detail in U.S. Pat. No. 5,387,103.

As best illustrated in FIG. 8, the divider means comprises severalcutting plates 90, having on each such cutting plate 90 a supportsurface 86. Each cutting plate 90 has a leading beveled edge 92, whichserves to cut the pliable material 8 into individualized sections 8a,8b, 8c and 8d. In a presently preferred embodiment, each of the cuttingplates 90 radially extend from a single longitudinal axis 94. Thelongitudinal axis 94 from which the cutting plates 90 radiate may becentered relative to the center of the barrel 12, or may be offset ifunequal volumes of sectionalized material are desired. Preferably, theleading beveled edge 92 of each cutting plate 90 lies and is situatedwithin barrel 12. Each cutting plate 90 also includes an oppositetrailing edge 96 which extends beyond the outlet end 22 of barrel 12.

The cutting plates are shown as being an integrally molded portion ofbarrel 12. However, those of skill in the art will note that other waysexist of installing a divider means. It is also noted that the cuttingplates 90 are concentric with the barrel 12. It is intended thatradially disposed cutting plates 90 extend from the longitudinal axis 94that is shared with the barrel 12 to the inside surface of the barrel12, such that substantially all of the material 8 that is within barrel12 will be divided into compartmentalized and sectionalized pieces 8a,8b, 8c and 8d.

The syringe apparatus 10 further includes a cap means 98 that can beselectively removable from, and placed over, the individualized sections8a, 8b, 8c and 8d of the pliable material 8 which have been presentedbeyond the outlet end 22 of the barrel 12. FIG. 1 shows the cap 98installed at the outlet end 22 of the barrel 12. FIG. 1 further showsthe cap 98 fitting tightly at its proximal end against the shoulder 26of barrel 12. The tight fit between the proximal end of cap 98 and theshoulder 26 of barrel 12 is to ensure that the composite material withinthe barrel 12 is not exposed to ambient conditions. Cap 98 also featuresa recessed internal surface (not shown) that overlays and covers allcompartmentalized individual sections 8a, 8b, 8c and 8d of the compositematerial 8 which extend beyond the outlet end 22 of barrel 12. FIG. 2shows the cap 98 having been removed from the outlet end 22 of thebarrel 12.

In the presently preferred embodiment, radially spaced cutting plates 90do not contact the internal recessed surface (not shown) of cap 98 so asto allow ample space for sections 8a, 8b, 8c and 8d when the cap 98 isinstalled. It is also noted that the cap 98 sealingly fits around theexternal surface of the distal end 22 of barrel 12 so that the compositematerial 8 within barrel 12 is sealed off from ambient conditions. In apreferred embodiment of the present invention, the radially spacedcutting plates 90 do not contact the top inside surface of cap 98, butdo contact the inside surface 88 of barrel 12.

A preferable and intended use of a presently preferred embodiment of thepresent invention is that the syringe apparatus 10 will be used toextrude therefrom a tooth composite material of a type that isessentially solid, yet pliable, and which cures when the material isexposed to an activating light. Other applications and uses of theapparatus are also possible, and are intended as within the scope of thepresent invention. Preferably, the barrel 12, the radially spaced vanesor cutting plates 90, and support surfaces 86, as well as cap 98 willall be constructed of or coated by a substance having a component thatblocks transmission of the activating light which causes the toothcomposite material 8 therein to begin curing.

In summary, the dental syringe system of the present invention enablesthe efficient storage and dispensing of solid, yet pliable materials,such as dental composites with a minimum of wasted material. The presentinvention also provides a syringe apparatus comprising a syringe barrelthat can be utilized with either a standard push-type plunger or beretrofitted for use with a threaded, rotation-type plunger. The presentinvention further provides a syringe apparatus that automaticallyrelieves the pressure built up within the syringe barrel when theexternal force is removed from the syringe plunger. The dental syringesystem also provides discrete and separated doses (or wedges) of a solidbut pliable extrudent as the material is extruded from the syringesystem. The doses are easily pinched off by a shaping tool against thesupport surfaces which extend beyond the outlet end of the barrel means.The barrel means, divider means, and cap means block transmissiveexposure of the material therein to an activating light so as to preventpremature curing of the light activated material therein.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

What is claimed and desired to be secured by United States Patent is: 1.A syringe apparatus that is convertible from a standard push-typesyringe into a type of syringe apparatus adapted for using a threadedplunger for delivery of a material of a type that is essentially solid,yet pliable, comprising:unthreaded barrel means for containing thematerial, the barrel means comprising an inlet end, an outlet end, andan enlarged finger grip at the inlet end; separate plug means forinsertion into the barrel means at the inlet end thereof; engaging meansfor slidable attachment over the separate plug means inserted into thebarrel means and for slidable attachment to the finger grip of thebarrel means so as to non-rotatably engage the finger grip and so as toenclose and hold the separate plug means within the barrel means, theengaging means having a threaded throughbore; and separate plunger meansfor contacting the separate plug means through the engaging means, andfor movement of the plug means through the barrel means, the plungermeans having a threaded portion that is complementary to the threadedthroughbore of the engaging means such that the plunger means may beadvanced into the barrel means at the inlet end by rotating the plungermeans through the threaded throughbore of the engaging means, therebyeffecting delivery of the material at the outlet end.
 2. The syringeapparatus as defined in claim 1, wherein the barrel means furthercomprises divider means for sectionalizing portions of the pliablematerial as it is pushed through the barrel means, and for individuallycompartmentalizing the sectionalized portions of the pliable material asit is pushed by the plunger means to the outlet end of the barrel means,such that the pliable material is presented beyond the outlet end of thebarrel means in a plurality of individualized sections, each saidindividualized section being contained in a separate compartment of thedivider means, and each said separate compartment having a supportsurface extending beyond the outlet end of the barrel means toaccommodate removal of a selected portion of the sectionalized andcompartmentalized part of the material.
 3. The syringe apparatus asdefined in claim 1, wherein the enlarged finger grip comprises anintegrally formed, first generally planar surface, orientedperpendicular to the longitudinal axis of the barrel means and having atleast two flat, parallel opposing edges.
 4. The syringe apparatus asdefined in claim 3, wherein the engaging means comprises a secondgenerally planar surface having at least two flat, parallel opposingsides with integrally formed channels along such at least two flat,parallel opposing sides, the channels being configured to receive theflat, parallel opposing edges of the first generally planar member insliding, press fit engagement.
 5. The syringe apparatus as defined inclaim 1, wherein the plunger means comprises a proximal end, a distalend, and a threaded stem located between the proximal end and the distalend, the threaded stem being complementary to the threaded throughboreof the engaging means.
 6. The syringe apparatus as defined in claim 5,wherein the threads of the threaded stem and the threads of the threadedthroughbore have a low coefficient of friction.
 7. The syringe apparatusas defined in claim 5, wherein the threads of the threaded stem and thethreads of the threaded throughbore have a pitch of not more than 10threads per inch.
 8. The syringe apparatus as defined in claim 5,wherein the teeth of the threaded stem and the teeth of the threadedthroughbore have a generally square-shaped cross section.
 9. In asyringe apparatus that is convertible from a standard push-type syringeinto a type of syringe apparatus adapted for using a threaded plungerfor delivering a material of a type that is essentially solid, yetpliable, said standard syringe having an unthreaded barrel means forcontaining the material, the barrel means comprising an inlet end, anoutlet end, and an enlarged finger grip at the inlet end, theimprovement comprising:separate plug means for insertion into the barrelmeans at the inlet end thereof; engaging means for slidable attachmentover the separate plug means inserted within the barrel means, and forslidable attachment to the finger grip of the barrel means so as tonon-rotatably engage the finger grip and so as to enclose and hold theseparate plug means within the barrel means, the engaging means having athreaded throughbore; and separate plunger means for contacting theseparate plug means through the engaging means, and for movement of theplug means through the barrel means, said plunger means having athreaded portion that is complementary to the threaded throughbore ofthe engaging means such that the plunger means may be advanced into thebarrel means at the inlet end by rotating the plunger means through thethreaded throughbore of the engaging means, thereby effecting deliveryof the material at the outlet end.
 10. The syringe apparatus as definedin claim 9, wherein the enlarged finger grip comprises an integrallyformed, first generally planar surface, oriented perpendicular to thelongitudinal axis of the barrel means and having at least two flat,parallel opposing edges.
 11. The syringe apparatus as defined in claim10, wherein the engaging means comprises a second generally planarsurface having at least two flat, parallel opposing sides withintegrally formed channels along such at least two flat, parallelopposing sides, the channels being configured to receive the flat,parallel opposing edges of the first generally planar member in sliding,press fit engagement.
 12. The syringe apparatus as defined in claim 11,wherein the threads of the threaded stem and the threads of the threadedthroughbore have a low coefficient of friction.
 13. The syringeapparatus as defined in claim 11, wherein the plunger means comprises aproximal end, a distal end, and a threaded stem located between theproximal end and the distal end, the threaded stem being complementaryto the threaded throughbore of the engaging means.
 14. The syringeapparatus as defined in claim 13, wherein the threads of the threadedstem and the threads of the threaded throughbore have a pitch of notmore than 10 threads per inch.
 15. The syringe apparatus as defined inclaim 14, wherein the teeth of the threaded stem and the teeth of thethreaded throughbore have a generally square-shaped cross section. 16.The syringe apparatus as defined in claim 9, wherein the barrel meansfurther comprises divider means for sectionalizing portions of thepliable material as it is pushed through the barrel means, and forindividually compartmentalizing the sectionalized portions of thepliable material as it is pushed by the plunger means to the outlet endof the barrel means, such that the pliable material is presented beyondthe outlet end of the barrel means in a plurality of individualizedsections, each said individualized section being contained in a separatecompartment of the divider means, and each said separate compartmenthaving a support surface extending beyond the outlet end of the barrelmeans to accommodate removal of a selected portion of the sectionalizedand compartmentalized part of the material.
 17. The syringe apparatus asdefined in claim 16, wherein the threads of the threaded portion and thethreads of the threaded thoughbore are such that one complete revolutionof the plunger means relative to the barrel means will apply sufficientpressure to the materials within the barrel to extrude a sufficientamount of the material from the outlet end of the barrel to completelyfill the compartments formed by the dividing means.
 18. A syringeapparatus that is convertible from a standard push-type syringe into atype of syringe apparatus adapted for using a threaded plunger fordelivery of a material of a type that is essentially solid, yet pliable,comprising:unthreaded barrel means for containing the material, thebarrel means comprising an inlet end, and outlet end, and an enlargedfinger grip at the inlet end, the enlarged finger grip comprising anintegrally formed, first generally planar surface, orientedperpendicular to the longitudinal axis of the barrel means and having atleast two flat, parallel opposing edges, the barrel means furthercomprising divider means for sectionalizing portions of the pliablematerial as it is pushed through the barrel means, and for individuallycompartmentalizing the sectionalized portions of the pliable material asit is pushed by the plunger means to the outlet end of the barrel meansin a plurality of individualized sections, each said individualizedsection being contained in a separate compartment of the divider means,and each said separate compartment having a support surface extendingbeyond the outlet end of the barrel means to accommodate removal of aselected portion of the sectionalized and compartmentalized part of thematerial; separate plug means for insertion into the barrel means at theinlet end thereof; engaging means for slidable attachment over theseparate plug means inserted into the barrel means and for slidableattachment onto the finger grip of the barrel means so as tonon-rotatably engage the finger grip and so as to enclose and hold theseparate plug means within the barrel means, the engaging meanscomprising a second generally planar surface having at least two flat,parallel opposing sides with integrally formed channels along such atleast two flat, parallel opposing sides, the channels being configuredto receive the flat, parallel opposing edges of the first generallyplanar member in sliding, non-rotatable press fit engagement, and theengaging means further comprising a threaded throughbore located on thesecond generally planar surface such that the threaded throughbore is inlongitudinal alignment with the barrel means when the finger grip isfully inserted into the engaging means; and separate plunger means forcontacting the separate plug means through the engaging means, and formovement of the plug means through the barrel means, the plunger meanshaving a threaded portion that is complementary to the threadedthroughbore of the engaging means such that the plunger means may beadvanced into the barrel means at the inlet end by applying an externalrotational force to the plunger means relative to the barrel means,thereby effecting delivery of the material at the outlet end.
 19. Amethod of assembling a syringe apparatus so as to convert the apparatusfrom a standard push-type syringe into a type of syringe apparatusadapted for using a threaded plunger for delivering a material of a typethat is essentially solid, yet pliable, said standard syringe having anunthreaded barrel means for containing the material, the barrel meanscomprising an inlet end, an outlet end, and an enlarged finger grip atthe inlet end, the method comprising the steps of:inserting a separateplug means into the barrel means at the inlet end thereof: sliding aseparate engaging means over the separate plug means inserted within thebarrel means, and attaching the separate engaging means onto the fingergrip of the barrel means so as to non-rotatably engage the separateengaging means to the finger grip and so as to enclose and hold theseparate plug means within the barrel means; and contacting the separateplug means through the engaging means with a separate threaded plungermeans, and moving the plug means through the barrel means by rotatingthe plunger means through a complementary threaded throughbore of theengaging means, thereby effecting delivery of the material at the outletend.